Studies of uranium carbide targets of a high density

Abstract

Production of Cs and Fr isotopes from uranium carbide targets of a high density has been investigated at IRIS (Investigation Radioactive Isotopes at Synchrocyclotron), Gatchina. The UC target material with a density of 12 g/cm3 was prepared in a form of pellets. Two targets were tested on-line under the same temperature conditions: (a) a reference small target with a thickness of 4.5 g/cm2; (b) a heavier (so called intermediate) target with a thickness of 91 g/cm2. Yields and release efficiencies of nuclides with half-lives from some minutes to some milliseconds produced by 1 GeV protons in these targets are presented. It is remarkable that yields, even those of very short-lived isotopes such as 214Fr (T1/2 = 5 ms) and 219Fr (T1/2 = 20 ms), increase proportionally to the target thickness. A one month off-line heating test of the 91 g/cm2 target at a temperature of 2000 °C has been carried out successfully. The yields and release efficiencies of Cs and Fr measured on-line before and after the heating test coincided within the limits of measurement errors, thereby demonstrating the conservation of the target unit parameters. Based on these very promising results, a heavier target with a mass about 0.7 kg is prepared presently at IRIS

Development of High Temperature and Mass-Separation Methods for Selective Production of Medical Radionuclides

“…Making use of beams of different bombarding particles -protons, neutrons, and heavy ions, the ISOL installations at present provide the production of considerably more than 2000 mass-separated isotopes of almost all elements of the periodic system. The on-line mass-separator facilities like ISOLDE (CERN, Switzerland) [6], ISAC (Isotope Separation and ACceleration, TRIUMF, Canada) [7], IRIS (Investigations of Radioactive Isotopes on Synchrocyclotron, PNPI, Gatchina) [8] and many others enabled the production of radioactive isotopes with half-lives from several milliseconds to several thousand years which are used for studying in nuclear physics, solid-state physics, and for some medical physics experiments. The first experiments on receiving mass-separated medical radionuclides for tests on animals [9,10] were made at the ISOLDE installation which is used in general for nuclear physics research.…”

“…A high-temperature method of extraction of 223,224 Ra produced by protons in 238 UC was described in detail in [11]. In our experiments, we used the UC target (uranium-238 mono carbide of a high density [8,11]) for production and a high-temperature extraction of radium isotopes. It was demonstrated that investigated target materials can be used as well for the massseparator target construction of the mass-separator station for production at RIC-80 radioisotope medical beams of very high purity.…”

NEW METHOD DEVELOPMENT FOR MEDICAL RADIONUCLIDE 223,224Ra, 225Ac PRODUCTION

“…The mass-separated isotopes 223,224 Ra and 225 Аc were produced at the ISOL facility IRIS (Investigation of Radioactive Isotopes at Synchrocyclotron) [9] working on-line with a 1-GeV proton beam of the synchrocyclotron of Petersburg Nuclear Physics Institute (Gatchina, Russia). 223,224 Ra and 225 Аc were produced in a UC target, ionized in a high-temperature surface ionization source, were extracted and accelerated by a 30 kV potential difference.…”

Status of the Project of Radioisotope Complex Ric-80 (Radioisotopes at Cyclotron C-80) at Pnpi

“…The main problem -the extraction and isotopic separation produced radio nuclides is under successful solution for almost 50 years already by means of ISOL installations at beams of different bombarding particles -protons, neutrons and heavy ions. Such on-line systems like ISOLDE (CERN, Switzerland), ISAC (TRIUMF, Canada), IRIS (PNPI, Gatchina) [2,3,4] operation on-line at proton beams, allows to obtain at present more than 2000 separated isotopes of almost all elements of the Periodic system. Produced radioactive isotopes with half-life from several milliseconds to several thousand years are used in nuclear physics study, in study of solid state physics and in the radiation medicine.…”